<template>
  <div class="q-pa-md">
    <q-table
      flat bordered
      title="Treats"
      :rows="rows"
      :columns="columns"
      color="primary"
      row-key="name"
    >
      <template v-slot:top-right>
        <q-btn
          color="primary"
          icon-right="archive"
          label="Export to csv"
          no-caps
          @click="exportTable"
        />
      </template>
    </q-table>
  </div>
</template>

<script>
import { exportFile, useQuasar } from 'quasar'

const columns = [
  {
    name: 'name',
    required: true,
    label: 'Dessert (100g serving)',
    align: 'left',
    field: row => row.name,
    format: val => `${val}`,
    sortable: true
  },
  { name: 'calories', align: 'center', label: 'Calories', field: 'calories', sortable: true },
  { name: 'fat', label: 'Fat (g)', field: 'fat', sortable: true },
  { name: 'carbs', label: 'Carbs (g)', field: 'carbs' },
  { name: 'protein', label: 'Protein (g)', field: 'protein' },
  { name: 'sodium', label: 'Sodium (mg)', field: 'sodium' },
  { name: 'calcium', label: 'Calcium (%)', field: 'calcium', sortable: true, sort: (a, b) => parseInt(a, 10) - parseInt(b, 10) },
  { name: 'iron', label: 'Iron (%)', field: 'iron', sortable: true, sort: (a, b) => parseInt(a, 10) - parseInt(b, 10) }
]

const rows = [
  {
    name: 'Frozen Yogurt',
    calories: 159,
    fat: 6.0,
    carbs: 24,
    protein: 4.0,
    sodium: 87,
    calcium: '14%',
    iron: '1%'
  },
  {
    name: 'Ice cream sandwich',
    calories: 237,
    fat: 9.0,
    carbs: 37,
    protein: 4.3,
    sodium: 129,
    calcium: '8%',
    iron: '1%'
  },
  {
    name: 'Eclair',
    calories: 262,
    fat: 16.0,
    carbs: 23,
    protein: 6.0,
    sodium: 337,
    calcium: '6%',
    iron: '7%'
  },
  {
    name: 'Cupcake',
    calories: 305,
    fat: 3.7,
    carbs: 67,
    protein: 4.3,
    sodium: 413,
    calcium: '3%',
    iron: '8%'
  },
  {
    name: 'Gingerbread',
    calories: 356,
    fat: 16.0,
    carbs: 49,
    protein: 3.9,
    sodium: 327,
    calcium: '7%',
    iron: '16%'
  },
  {
    name: 'Jelly bean',
    calories: 375,
    fat: 0.0,
    carbs: 94,
    protein: 0.0,
    sodium: 50,
    calcium: '0%',
    iron: '0%'
  },
  {
    name: 'Lollipop',
    calories: 392,
    fat: 0.2,
    carbs: 98,
    protein: 0,
    sodium: 38,
    calcium: '0%',
    iron: '2%'
  },
  {
    name: 'Honeycomb',
    calories: 408,
    fat: 3.2,
    carbs: 87,
    protein: 6.5,
    sodium: 562,
    calcium: '0%',
    iron: '45%'
  },
  {
    name: 'Donut',
    calories: 452,
    fat: 25.0,
    carbs: 51,
    protein: 4.9,
    sodium: 326,
    calcium: '2%',
    iron: '22%'
  },
  {
    name: 'KitKat',
    calories: 518,
    fat: 26.0,
    carbs: 65,
    protein: 7,
    sodium: 54,
    calcium: '12%',
    iron: '6%'
  }
]

function wrapCsvValue (val, formatFn, row) {
  let formatted = formatFn !== void 0
    ? formatFn(val, row)
    : val

  formatted = formatted === void 0 || formatted === null
    ? ''
    : String(formatted)

  formatted = formatted.split('"').join('""')
  /**
   * Excel accepts \n and \r in strings, but some other CSV parsers do not
   * Uncomment the next two lines to escape new lines
   */
  // .split('\n').join('\\n')
  // .split('\r').join('\\r')

  return `"${formatted}"`
}

export default {
  setup () {
    const $q = useQuasar()

    return {
      columns,
      rows,

      exportTable () {
        // naive encoding to csv format
        const content = [columns.map(col => wrapCsvValue(col.label))].concat(
          rows.map(row => columns.map(col => wrapCsvValue(
            typeof col.field === 'function'
              ? col.field(row)
              : row[ col.field === void 0 ? col.name : col.field ],
            col.format,
            row
          )).join(','))
        ).join('\r\n')

        const status = exportFile(
          'table-export.csv',
          content,
          'text/csv'
        )

        if (status !== true) {
          $q.notify({
            message: 'Browser denied file download...',
            color: 'negative',
            icon: 'warning'
          })
        }
      }
    }
  }
}
</script>
